Symptoms

When you use volumes that use the NTFS file system on integrated device electronics (IDE) drives with caching enabled, you may receive the following error message during startup:

Stop 0x000000EDUnmountable_Boot_Volume

The normal recovery process in such a case is to run the chkdsk /r command from Recovery Console, and then continue. On OEM versions of Windows XP, the Recovery Console may not be accessible. If this fix has not been included in the OEM build of Windows XP, you may not be able to enter Recovery Console and run the chkdsk /r command for recovery. For additional information, click the article number below to view the article in the Microsoft Knowledge Base:

308402 Cannot Log On to Recovery Console After Running Sysprep in Windows XP

Cause

Because of the write-pattern optimization in IDE disk drives, the caching routines sometimes write data out of order to keep drive write speeds at the fastest possible level depending on where data is located on the disk. This opens a timing window where the NTFS disk system could have critical tables damaged if a write is not finished. Microsoft has recommended in the past that caching on IDE drives be turned off on programs with somewhat critical data that is stored on the disk or for situations that allow the slight drop in overall speed. Programs with critical data may need to use SCSI drives, which have better control of data transactions.

Resolution

To resolve this problem, obtain the latest service pack for Windows XP. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file.

The English version of this fix should have the following file attributes or later:

Status

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Windows XP Service Pack 1.

More Information

Changes that are made to key system files allows the system volume to continue to mount to a point where the chkdsk command can be run. These files should be loaded as soon as possible before the problem happens. If you experience this problem, you may need to obtain and use system recovery software that is available from the computer manufacturer.